It's one of these, possibly the 24 hour block - it sounds like maybe someone got your password and used your account for spamming - and as a precaution, you should change your hotmail password immediately.
I was trying to send mail via a newly created account. Microsoft's error messages are about as meaningful as the original "bad command or filename" daftness of Windows 95!
After much digging it turned out that I should have verified the account (on Outlook.com) and then the mail was allowed to be sent! Surely they could have just said "if you're the owner, pls verify your account on outlook.com", instead of wasting half a day of my time!??
After much digging it turned out that I should have verified the account and then the mail was allowed to be sent! Surely they could have just said "if you're the owner, pls verify your account on outlook com", instead of wasting half a day of my time!??
how did you do that if I may ask. I think I am kind of dealing with a similar problem. I have this Office 365 account now for a week or so and cofigured Thunderbird as my mail client and everything worked fine until yesterday.
All the messages I try to send seem to be rejected by the SMTP server. Only on thunderbird, sending messages through the web app still works fine. In thunderbird I always get this message (translation of the italic parts by myself):
Sending message failed. The server responded: 5.3.4 Requested action not taken; To continue sending messages, please sign in to your account.. Please check the message and try again.
On the outlook.com (Hotmail) side, I've seen this type of rejection: "Requested action not taken; To continue sending messages, please sign in to your account" mean you needed to log in and complete a captcha to authenticate. But haven't seen it on the office365/Exchange side.
I'm assuming you are under the daily limit for sent messages - it's fairly high on the Exchange side, but new accounts may have lower limits (in the hundreds). If it's this, it resets every 24 hours - it will work for awhile, then quit, then work again.
Check your SMTP settings in T-Bird - are they correct? I believe it uses port 587 and SSL and you need to use outbound authentication.